Question

c#如何从根本上防止重复提交相同的数据

Answer 1

C#禁止重复提交
1:连续2次提交 Button1.Attributes.Add("onclick", "this.value='正在提交中，请等待……';this.disabled=true;" + this.GetPostBackEventReference(Button1));

2:刷新提交： Response.Write(" <script language=javascript> alert( '采购成功 ');window.location.href=window.location.href; </script> ");

也可以做成自定义控件：
/**//// <summary>
/// 只能提交一次的按钮
/// </summary>
public class ButtonSubmitOnce : Button
{
private string _textonclick = "处理中，请稍后。。。";
private string _clientcheck;

protected override void Render(HtmlTextWriter writer)
{
StringBuilder temp = new StringBuilder();

temp.Append(this.OnClientClick);

if (!string.IsNullOrEmpty(_clientcheck)) temp.Append("if(!").Append(_clientcheck).Append(") return false;");

if (!string.IsNullOrEmpty(_textonclick)) temp.Append("this.value=\"").Append(_textonclick).Append("\";");

//this is for the ff
temp.Append("if(null==window.onunload) window.onunload = function(){};");

temp.Append("this.disabled = true;").Append(Page.GetPostBackEventReference(this));

this.OnClientClick = temp.ToString();

base.Render(writer);
}

public string TextOnClick
{
set { _textonclick = value; }
}

public string ClientCheck
{
set { _clientcheck = value; }
}
}

Answer 2

防止按钮重复按，就开始设置为false，完成方法后true。如果是数据库，就判断数据是否存在，存在就不提交